Such a tranmitter is known from the High-Definition Multimedia Interface (HDMI) standard that provides several methods for carrying auxiliary data in auxiliary data channels in addition to the video pixel stream, either multiplexed in the TMDS stream (such as for audio, and signalling (InfoFrames)) or, on separate wires (such as using CEC). HDMI implements the EIA/CEA-861 standards, which define video formats and waveforms, transport of compressed, uncompressed, and LPCM audio, auxiliary data, and implementations of the VESA EDID.[2][3] CEA-861 signals carried by HDMI are electrically compatible with the CEA-861 signals used by the digital visual interface (DVI)
The HDMI standard has the disadvantage that all of the auxiliary channels are asynchronous to the video and in practical implementations the HDMI receiving circuits are connected to their target subsystems using a different connection bus to that of the video. Hence they cannot be used to deliver auxiliary data in a manner which is synchronous with the video.
However, there are some applications that require auxiliary data to be e.g. frame-accurate with the video stream and which cannot be carried in time by the existing asynchronous mechanisms described in HDMI 2.0 and earlier, especially using the current architecture of HDMI transmitter and receiver components. Examples of such applications are frame-accurate disparity and occlusion information for so-called 3D video; or additional high dynamic range or colour gamut information. These applications require an amount of data that is significantly smaller than the video contained within the video frame but which must be provided and processed at the same time as the video data for that frame.
HDMI from version 1.3 onwards allows for a colour depth of up to 16 bits per colour per pixel (bcp). Standard video content usually uses 8 bcp and so-called “Deep Colour” applications use 10, 12 or 16 bcp. It is therefore possible to use some of the bits targeted for the extended colour depth to carry some extra data rather than video data (see <EP2235956>). This is capable of carrying pixel-accurate information at much higher data rates than is required by the above-mentioned applications, so this would be wasteful of resources in the devices, and on the HDMI cable. Moreover, current practical implementations are not capable of handling the necessary high colour depths that would be needed.
EP1231795A2 discloses usig an abbreviated blanking period, in comparison to the standard VESA and CEA-EIA blanking periods, in order to send data, including low bandwidth, non-timing information, over one or more channels of the digital video link. By shortening the blanking period, the amount of time available for sending data in each scan line is increased, enabling the system to send more data over each channel. The inactive video portion of a scan line sent during vertical sync may also be used to send additional digital data. Shortening the blanking periods and/or using the inactive video sections of the horizontal scan lines adds to the overall data capacity of the link and may be used to send other digital data, such as multi-channel audio, video, control, timing, closed captioning or other digital data.
US2010/157169A1 makes it possible to control a CEC-non-compliant device connected to a television receiver by using a remote control sender of the television receiver. [Solving Means] The fact that a physical address [2000] is a device (Recording Device) that a photo player 370B controls in place of the physical address [2000] is set by a user in the photo player 370B. In accordance with this setting, the photo player 370B decides a logical address {1} as a CEC-controlled Recording Device. When the user operates a disc recorder 21 OB that is a CEC-non-compliant device by using a remote control sender 277, a television receiver 250B generates a CEC control command addressed to the disc recorder 210B. The photo player 370B detects the CEC control command, converts the CEC control command into an infrared remote control command, and sends the infrared remote control command from an infrared sending unit 384 to the disc recorder 210B.
In JP2011146929A one frame of video of each system is inserted to the multiplexed video frame being a video frame with a larger screen size, and transmitted as the data of the multiplexed video frame. Audio data of each system is divided by each sample inputted within a time corresponding to one frame period of the multiplexed video frame and inserted to the multiplexed video frame. In each multiplexing circuit, the information concerning the arrangement position in the multiplexed video frame in data of each system and the information concerning the format of data of each system are inserted to the multiplexed video frame. The method is applied to a video acoustic apparatus for processing audio data of a plurality of systems.
It is an objective of this invention to transmit the auxiliary information synchronously with the video data using the existing using the current architecture of HDMI transmitter and receiver components.